English

Singmaster's conjecture in the interior of Pascal's triangle

Number Theory 2023-01-13 v1

Abstract

Singmaster's conjecture asserts that every natural number greater than one occurs at most a bounded number of times in Pascal's triangle; that is, for any natural number t2t \geq 2, the number of solutions to the equation (nm)=t\binom{n}{m} = t for natural numbers 1m<n1 \leq m < n is bounded. In this paper we establish this result in the interior region exp(log2/3+εn)mnexp(log2/3+εn)\exp(\log^{2/3+\varepsilon} n) \leq m \leq n-\exp(\log^{2/3 + \varepsilon} n) for any fixed ε>0\varepsilon > 0. Indeed, when tt is sufficiently large depending on ε\varepsilon, we show that there are at most four solutions (or at most two in either half of Pascal's triangle) in this region. We also establish analogous results for the equation (n)m=t(n)_m = t, where (n)m:=n(n1)(nm+1)(n)_m := n(n-1)\ldots(n-m+1) denotes the falling factorial.

Keywords

Cite

@article{arxiv.2106.03335,
  title  = {Singmaster's conjecture in the interior of Pascal's triangle},
  author = {Kaisa Matomäki and Maksym Radziwiłł and Xuancheng Shao and Terence Tao and Joni Teräväinen},
  journal= {arXiv preprint arXiv:2106.03335},
  year   = {2023}
}

Comments

33 pages

R2 v1 2026-06-24T02:53:45.411Z